class_docstr: Returns a sequentially numbered ID based on a prefix.
code: def __str__(self) -> str:
      return f"{self.id_prefix.value}_{self.index}"
  
file_path: metricflow/metricflow/dag/prefix_id.py
imports: from __future__ import annotations
  import threading
  from dataclasses import dataclass
  from typing import Dict
  from typing_extensions import override
  from metricflow.dag.id_prefix import IdPrefix
label_desc: Use image node_id 1 for calling the SequentialId obj's underlying member method code with example usage: obj.__str__() and returns: self, str, self